Instinctive specialized learning (in Phoebes and other critters)

We are watching a Phoebe rebuilding last year's nest on our Observatory (in a nice safe place by the way, another instinct). This rebuilding may well require different materials than building a nest from scratch, but the amazing thing we saw was where the bird went to get these materials.

We are on a small rise, facing a field where the horses graze. Beyond the field, directly in front of us, grows a row of dense bushes. The same is true for the field border to our right, which is at 90 degrees to the far border. Both borders are well over a hundred yards away, a considerable distance indeed.

First the Phoebe made two successive trips to the bushes across from us, bringing back materials each time. It went to roughly the same place and may well have gone to exactly the same place. Then it abruptly changed behavior and went to the bushes on our right, far away from where it had gone before, again returning with materials. Moreover, on each trip the bird spent only about 10 to 20 seconds finding and collecting the material.

Clearly this bird knew what it wanted and where to get it, despite it being (1) a long way away and (2) in two very different places. The bird must have had detailed advanced knowledge in order to do this. It must have spent some time, perhaps a lot of time, surveying the surrounding area and locating suitable materials, before beginning this round of nest building.

This pre-knowledge behavior implies an instinct to learn. Perhaps something of the form "go forth and locate nest building materials."

And of course the bird must remember what it has learned. I recall noting this long distance behavior last year. Perhaps the bird located the suitable materials then.

Note that this concept of locating suitable nest materials in advance is more abstract than simply needing something specific for a nest that is under construction. Nests can be built from a variety of materials. In fact it may be that the Phoebe builds its nest based on the materials it has previously located.

I am inclined to think that the instinct to learn like this is widespread in animals. What is especially interesting here is that it is an instinct to learn something highly specialized. This too may well be common. For example, I earlier discussed the horses deciding to explore a new field, that is to learn about it, rather than begin grazing. Then too there is the case of horses changing fields to graze on a particular plant, which they clearly already knew about.

The instinct to learn is certainly a concept worth exploring further.

Horse face communication is complex

The University of Sussex has done some great research on how horses communicate using facial expressions, just as humans do. In fact some of these expressions are similar between humans and horses. Others are different, such as the horse's use of its very mobile ears.

The research has been done by Professor Karen McComb and her students at the Mammal Vocal Communication and Cognition Research Group. Here is part of a Science Daily news article about some of their work:

"Horses are sensitive to the facial expressions and attention of other horses, including the direction of the eyes and ears. The findings are a reminder for us humans to look beyond our own limitations and recognize that other species may communicate in ways that we can't, the researchers say. After all, human ears aren't mobile."

https://www.sciencedaily.com/releases/2014/08/140804123009.htm

They even found that horses are able to distinguish between angry and happy human facial expressions. Here is an article about that work:
https://www.sciencedaily.com/releases/2016/02/160209221158.htm

The point for us here is that the horse's understanding of other horse's (or people's) expressions is instinctive, not learned. For that matter it is instinctive in people as well. There are a lot of different expressions, so this is a complex body of instinctive knowledge.

McComb's group has even done impressive anatomical work toward cataloging these expressions. See this article:
https://www.sciencedaily.com/releases/2015/08/150805144820.htm

We have certainly observed a lot of facial expressions in observing our horses, especially the ears, which can be quite active. Given this research we will pay more attention to these expressions and the behaviors they are involved with.

It would be very interesting to know, in some sense, how many expressions there are and what they mean. Again, the point is not that the horses know how to do these expressions, but that they know what they mean when other horses do them.

The expression itself may not involve knowledge, but the communication certainly does. This seems like a sizable body of instinctive knowledge. As with our other examples, imagine trying to build a robotic horse that responds correctly to the facial expressions of real horses. No mean feat that would be.

Behavior based cognition: the Research Program

The previous three posts suggest that even trees exhibit cognition. In a way what we are doing here is a form of behaviorism. We are looking at behavior and asking what concepts and decision rules this behavior requires?

Classical behaviorism, which is now almost a hundred years old, posited stimulus and response mechanisms to explain behavior. In contrast, we are drawing on much more recent advances in artificial intelligence, especially robotics and expert systems.

These technologies have led scientists and engineers to think deeply about what is required to produce even seemingly simple human behaviors. What I am proposing is a straightforward extension of this research, to include animal behavior. Perhaps even plant behavior as well, but that is really more of an aside.

I am not concerned with thinking or mental processes in general. The point is simply that a given behavior requires certain concepts and decision making.

For example, a bird cannot build a nest without first finding and choosing a nest site. This behavior requires seeking, recognition and decision. The bird has to know what a good nest site looks like. Moreover it gets this knowledge via instinct. As we have said from the beginning, instinct is a way of knowing such things, an alternative to learning.

If we look closely and think about it, everywhere we look we see animals exhibiting this sort of behavior. The research question is how to unpack it? That is, how do we describe the concepts and decision rules that underlie this behavior?

Crown Shyness

The fact that trees do not rub on each other is known as "crown shyness." Google Scholar lists about 200 scientific journal articles using the term "crown shyness":

http://scholar.google.com/scholar?as_sdt=1,49&q=%22crown+shyness%22&hl=en&as_vis=1

A nice little literature. One abstract says the issue was first identified in the 1920s, making it almost 100 years old. Cool! The prevailing theory seems to be that the trees touch when the wind blows so stop growing, although this is questioned and crown shyness is often termed a mystery. 

So this is a known issue. However, what I observe is much more complex than a "crown shyness" where the branches simply stop growing. They change direction and keep growing, forming intricate avoidance structures. 

Trees avoid rubbing on other trees

If you go into a deciduous forest and look up you will see what appears at first glance to be a complex tangle of of branches. This is the forest canopy, where the trees compete for light.

On closer inspection, however, one finds a remarkable feature. This is that very few of the branches from any given tree rub on the branches from its neighbors.

In fact it appears to me that much of the complexity in the way the branches have grown is specifically to avoid rubbing on a neighbor. Rubbing is dangerous for a tree, because it creates the equivalent of an open wound. in many cases a branch will actually change direction, in a way that seems designed specifically to avoid a neighboring branch. Or so it seems to me.

Of course there are exception and some rubbing does occur. I think this is analogous to people accidentally bumping into things or other people. But if you took two open grown trees and moved them together there would be a tremendous amount of contact. That this does not occur when the trees grow close together is thus quite remarkable. If they grew as though their neighbors were not there, there would be a lot of rubbing.

If the trees actually grow so as to avoid rubbing on their neighbor's branches, then they must know where those branches are, without touching them. In the last post I discussed the idea that trees know where their parts are and grow them so as to maintain their balance. Now it seems that the deciduous also know where their neighbor's parts are, and they grow so as to avoid rubbing on them.

This all sounds rather farfetched, but I have difficulty coming up with any other explanation for this apparent growth behavior. Perhaps it is a function of the way the neighboring trees affect the light. In any case it is certainly a challenging research question.

Seeing Tree Growth As Behavior (part 1)

Over the years I have observed some interesting forms of growth in trees, which have the aspect of behavior, as opposed to simple growth.

First is what is called an oxbow. Here the tree's leader is damaged, so another branch curves upward to become the new leader. What is remarkable is that the new leader first curves backward, then straightens upward, so that it is positioned directly above the lower trunk. Somehow the new growing leader knows where the lower trunk is. I once had a large collection of oxbows from downed trees in a small patch of boreal forest, indicating they are not a rare or chance occurrence.

Note that there is a good reason for this behavior, which is balance. If the upper trunk grew some distance out from the lower trunk then the tree would be unbalanced. Wind is a great threat to trees, so balance is important. This is probably why open grown trees brow symmetrically, even at mid-latitudes where the sun is always on just one side. My conjecture is that the trees growth in general is a tradeoff between balance and efficient solar collection.

I observed another case of apparent balance when I began building a log cabin on a remote island in Northern Ontario, in the Boreal forest. I started with several spruce trees that grew along the shore, on the edge of the island's forest. Because of their location, their branches on the open or water side were much larger than those branches on the forest side, probably because the open side is where the sunshine was.

When I limbed them I found that they were unusable because the trunks were curved. The trees had actually grown so as to lean backward, toward the forest and away from their heavy side, just a a person would do if holding a weight out in front of them. By doing this they were more balanced.

What this suggests is that trees somehow know where their various parts are and can control their growth in order to achieve overall balance. If so then their growth is something like behavior.

Behaviorism versus Artificial Intelligence

Never having taken a psych course, I know very little about behaviorism, except that it stresses observable behavior. As a scientific method it is almost a hundred years old.

However, the rise of artificial intelligence provides us with a new set of tools and approaches. These include expert systems, knowledge engineering, decision modeling and robotics. Given these tools we can ask questions like what does a horse or other animal have to understand or decide in order to do what it does?

I am particularly interested in the instinctive understanding that leads to complex behavior, many cases of which we have already discussed. My impression is that behaviorism tends to focus on relatively simple behaviors, looking for things like stimulus-response, conditioning, etc. If so then I am looking at something different.

In any case my understanding is that the behaviorist study of animals was a reaction to, and a rejection of, what was deemed anthropomorphism. This is the attribution of human characteristics to animals (among other things).

My argument here is quite the opposite, in its way. That is, I think that animals understand a great deal more than humans do, in those instinctive areas that they specialize in. That is, we humans do not understand what these animals understand.

For example, I have no idea how to build a bird nest and certainly could not find and pick the right materials to do so. I actually tried to build a beaver dam once, at a time when I was an expert on designing earth dams. It was an abject failure, because a beaver dam is much more complex structurally than a human earth dam is. Yet the beaver does it with ease and without learning from others.

Moreover, I have seen beaver dams built from a wide variety of materials, depending on what was locally available. In short the beaver knows instinctively what to do, with what it has. That is expertise.

So what I am proposing is possibly a new approach to understanding animal behavior. It is an approach that sees animals as instinctive experts in those things that mean the most to them. Things that humans do not understand.